Huanglian, Coptis spp., a traditional drug in the oriental region, is the root of barberry shrub and has been used as a drug for conjunctivitis, diarrhoea etc., from ancient times. The present invention provides novel compounds having antibiotic activities, which is related to berberine, i.e., alkaloid component of Huanglian, Coptis spp.
Berberine chloride exhibits antibacterial activity against Gram-negative or Gram-positive bacteria, such as Staphylococcus aureus, Staphylococcus hemolyticus, Salmonella typhosa, Shigella dysenteriae, Shigella paradysenteriae, Escherichia coli, Neisseria gonorrhoeae or Diplococcus pneumoniae [Ukita T, Mizuno D, Tamura T, Jpn J Exp Med 20, 103 (1949)]. It has been reported that quaternary ammonium salt of berberine is prerequisite to the above antibacterial activity, and that the derivatives which do not contain such quaternary ammonium salt, for example, tetrahydroberberine exhibits less effect [Pitea. M, Margineanu C, Clujul Med 45, 465(1972)].
In addition, it has been reported that berberine sulfate inhibits the growth of fungi, such as Alternaria sp., Aspergillus flavus, Aspergdlus fumigatus, Candida albicans, Curvularia sp., Drechslera sp., Fusarium sp., Mucor sp., Penicillium sp., Rhizopus oryzae, or Scopulariopsis sp. at 10-25 mg/ml [Mahajan V M, Sharma A, Rattan A, Sabouraudia 20, 79 (1982)], and that berberine sulfate is also effective in case of oral administration of 350-700 mg/kg for mice infected with Candida albicans [Mirska I, Kedzia H, Kowalewski Z, Kedzia W, Arch Immunol. Ther Exp 20, 921 (1972)].
However, the antifungal activities of the compounds disclosed in the above prior arts are too weak. Moreover, berberine sulfate exhibits intense toxicity and thereby may cause a harmful or lethal effect on human in case of being dosed excessively. Accordingly, the present invention is contrived to solve these disadvatages.